EDF said Paluel’s outage may last longer due to a technical issue requiring a new and complex maintenance process.

The Paluel 2 reactor in the north of France has been offline since October 2019 for planned upgrade and maintenance and was originally expected to resume production at the end of December.

EDF said outages at its Flamanville 1 and 2 nuclear reactors also in the north of France were extended until May 31 from mid-April, adding that the “shutdown duration may extend due to complex maintenance activities.”

Flamanville 1 has been offline since September 2019, and Flamanville 2, since Jan. 10, 2019.

French nuclear safety agency ASN placed both reactors at the Flamanville nuclear power plant under increased surveillance in September following what it said were shortcomings in maintenance and contractor oversight.

EDF expects its nuclear power generation at between 375 terawatt hour (TWh) and 388 TWh this year after missing its target in 2019 due to prolonged unplanned outages and a complex maintenance schedule. (Reporting by Bate Felix and Forrest Crellin; Editing by Edmund Blair)